The Favor (1994)

Synopsis: Best friends Kathy (Harley Jane Kozak) and Emily (Elizabeth McGovern) are having disparate relationship troubles. Kathy is growing bored with her comfortable married life with husband Peter (Bill Pullman) while Emily is tired of her unstable arrangement with drifter artist Elliott (Brad Pitt). When Kathy hears her old flame Tom (Ken Wahl) will be attending their high school reunion, she asks Emily to seduce him and see what she's missing out on. Predictably, this leads to a mess of new problems.